<script>
  var xhr = new XMLHttpRequest();
  xhr.open('POST', 'test.php?a=1&b=2');
  xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
  xhr.send('c=3&d=4');
</script>
<a href="../首页/page10.html">
  <h2>返回上一页面</h2>
</a>